Astronomers have discovered the first yellowish-green white dwarf star, designated WD J1330+6435, located roughly 280 light-years away in the constellation Draco. The star acquired its unusual yellowish-green color after absorbing rocky debris from previously orbiting planets, altering how its high-density atmosphere absorbs light.
For the first time, researchers have documented a star displaying a yellowish-green hue, showing how a star's chemical makeup directly shapes its visible color. The object of interest, identified as “WD J1330+6435”, sits within the Milky Way at a distance of approximately 280 light-years from Earth.
White Dwarf Density Changes How Sodium Absorbs Light
White dwarfs represent the dense, exhausted cores of stars that have depleted their nuclear fuel and shed their outer layers. While most appear white, their surface colors can shift over time as their elemental composition changes.
That heavy accumulation alters the physics of light absorption. According to Hollands, the extreme density of the white dwarf’s atmosphere changes how sodium atoms interact with light. Instead of taking in a narrow slice of orange, the atoms pull in a much broader band spanning yellow, orange, and select red wavelengths. That shift leaves behind a distinctive yellowish-green glow.
Cataloging White Dwarf Colors in RAS Techniques and Instruments
The findings were published in the journal RAS Techniques and Instruments
as part of a broader research initiative aimed at mapping the actual colors human eyes might perceive when looking at white dwarfs. That study examined 151 white dwarfs, revealing that variations in their atmospheric envelopes produce a surprising palette that includes pink, violet, yellow, and sky blue.
Researchers also identified another notable white dwarf, cataloged as “WD J1011+2845”, situated about 48 light-years from Earth. That candidate may be among the reddest stars, shining in a salmon-tinted pink color driven by carbon rising from its interior to the surface and altering its outgoing light.
The universe may present unusual phenomena that rival what science fiction imagines.
Hollands noted that the array of stellar colors provides researchers with fresh pathways for understanding both chemical structures and the long-term history of planetary systems that once surrounded these stellar remnants.
